TREATMENT OF ACUTE AORTIC DISSECTIONS WITH EXPANDABLE METALLIC STENTS- EXPERIMENTAL-STUDY

PURPOSE: This experimental study was designed to evaluate the effectiv eness of metallic stents for the treatment of acute aortic dissection. MATERIALS AND METHODS: Thoracic aortic dissections were created in 14 mongrel dogs. Aortography performed immediately after creation of dis sections showed two types of aortic dissections: rapid flow in the fal se lumen (group 1) and slow flow in the false lumen (group 2). Each gr oup consisted of seven dogs. For each group, expandable metallic Giant urco stents were placed in five dogs and two dogs were used as control s. RESULTS: A week later, false lumina were patent in all dogs in grou p 1 and thrombosed in all dogs in group 2. In group 1, the mean diamet er of the true lumina was considerably enlarged from 5.9 mm +/- 1.6 to 9.9 mm +/- 2.8 and that of the false lumina significantly diminished from 9.1 mm +/- 1.3 to 5.2 mm +/- 2.3 (P < .05) after stent placement. In group 2, the true lumina were significantly dilated (5.2 mm +/- 2. 3 vs 12.3 mm +/- 3. 1, P < .05) and the false lumina disappeared compl etely (9.2 mm +/- 3.3 vs 0.0 mm, P < .0 1). Furthermore, the two contr ol dogs in group 2 died of visceral ischemia due to the compression of the true lumen by the thrombosed false lumina, but the dogs with sten ts showed no symptoms of the visceral ischemia. CONCLUSION: Expandable metallic stents are not effective in obliterating the false lumen in acute aortic dissection but may be useful in maintaining the blood flo w in the true lumen and avoiding visceral ischemia.